Add helper functions to create fake META entries in unit tests.
Add helper functions to create fake META entries in unit tests.

Change-Id: I930409ebc62d610e5c51583500994a1b557138a1

StumbleUponArchive/asynchbase,hzy001/asynchbase,tsuna/asynchbase,hhshuai/asynchbase,pythian/asynchbase,mapr/asynchbase,mway08/asynchbase,SteamShon/asynchbase,angushe/asynchbase,manolama/asynchbase,manolama/asyncbigtable,adityakishore/asynchbase,OpenTSDB/asynchbase,OpenTSDB/asynchbase,hhshuai/asynchbase,manolama/asynchbase,OpenTSDB/asyncbigtable,nvoron23/asynchbase,Flipboard/asynchbase,Connexity/asynchbase,yuzhu712/asynchbase,tempbottle/asynchbase,mapr/asynchbase,nvoron23/asynchbase,hzy001/asynchbase,mway08/asynchbase,Flipboard/asynchbase,tsuna/asynchbase,angushe/asynchbase,tempbottle/asynchbase,yuzhu712/asynchbase,SteamShon/asynchbase,Connexity/asynchbase,adityakishore/asynchbase,StumbleUponArchive/asynchbase